/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * http://www.gnu.org/copyleft/gpl.html
 */
package terra.database;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.logging.Logger;

public abstract class DatabaseFactory {
	private static final Logger _log = Logger.getLogger(DatabaseFactory.class
			.getName());

	protected enum ProviderType {
		MySql, MsSql
	}

	// =========================================================
	// Data Field
	protected static DatabaseFactory _instance;
	protected ProviderType _providerType;

	// =========================================================
	// Property - Public
	public static DatabaseFactory getInstance() throws SQLException {
		if (_instance == null){
				_instance = new DatabaseFactory_c3p0();
		}
		return _instance;
	}

	public final String prepQuerySelect(String[] fields, String tableName,
			String whereClause, boolean returnOnlyTopRecord) {
		String msSqlTop1 = "";
		String mySqlTop1 = "";
		if (returnOnlyTopRecord) {
			if (getProviderType() == ProviderType.MsSql)
				msSqlTop1 = " Top 1 ";
			if (getProviderType() == ProviderType.MySql)
				mySqlTop1 = " Limit 1 ";
		}
		String query = "SELECT " + msSqlTop1 + safetyString(fields) + " FROM "
				+ tableName + " WHERE " + whereClause + mySqlTop1;
		return query;
	}

	public final String safetyString(String... whatToCheck) {
		// NOTE: Use brace as a safty precaution just incase name is a reserved
		// word
		final char braceLeft;
		final char braceRight;
		if (getProviderType() == ProviderType.MsSql) {
			braceLeft = '[';
			braceRight = ']';
		} else {
			braceLeft = '`';
			braceRight = '`';
		}

		int length = 0;

		for (String word : whatToCheck) {
			length += word.length() + 4;
		}
		final StringBuilder sbResult = new StringBuilder(length);
		for (String word : whatToCheck) {
			if (sbResult.length() > 0) {
				sbResult.append(", ");
			}
			sbResult.append(braceLeft);
			sbResult.append(word);
			sbResult.append(braceRight);
		}
		return sbResult.toString();
	}

	public Connection getConnection() throws SQLException {
		return getConnection(true);
	}

	public final ProviderType getProviderType() {
		return _providerType;
	}

	public static void close(Connection con) {
		if (con == null)
			return;

		try {
			con.close();
		} catch (SQLException e) {
			_log.severe("Failed to close database connection! " + e);
		}
	}

	public abstract void shutdown();

	public abstract Connection getConnection(boolean checkclose)
			throws SQLException;

	public abstract Connection getConnection(long max_connection_time)
			throws SQLException;

	public abstract int getBusyConnectionCount() throws SQLException;

}
